Message ID | 20230414142341.354556-11-shiyn.lin@gmail.com (mailing list archive) |
---|---|
State | New |
Headers | show
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(2001-b011-20e0-1499-8303-7502-d3d7-e13b.dynamic-ip6.hinet.net. [2001:b011:20e0:1499:8303:7502:d3d7:e13b]) by smtp.googlemail.com with ESMTPSA id h7-20020a17090ac38700b0022335f1dae2sm2952386pjt.22.2023.04.14.07.25.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Apr 2023 07:25:53 -0700 (PDT) From: Chih-En Lin <shiyn.lin@gmail.com> To: Andrew Morton <akpm@linux-foundation.org>, Qi Zheng <zhengqi.arch@bytedance.com>, David Hildenbrand <david@redhat.com>, "Matthew Wilcox (Oracle)" <willy@infradead.org>, Christophe Leroy <christophe.leroy@csgroup.eu>, John Hubbard <jhubbard@nvidia.com>, Nadav Amit <namit@vmware.com>, Barry Song <baohua@kernel.org>, Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, "H. Peter Anvin" <hpa@zytor.com>, Steven Rostedt <rostedt@goodmis.org>, Masami Hiramatsu <mhiramat@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Arnaldo Carvalho de Melo <acme@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>, Ian Rogers <irogers@google.com>, Adrian Hunter <adrian.hunter@intel.com>, Yu Zhao <yuzhao@google.com>, Steven Barrett <steven@liquorix.net>, Juergen Gross <jgross@suse.com>, Peter Xu <peterx@redhat.com>, Kefeng Wang <wangkefeng.wang@huawei.com>, Tong Tiangen <tongtiangen@huawei.com>, Christoph Hellwig <hch@infradead.org>, "Liam R. Howlett" <Liam.Howlett@Oracle.com>, Yang Shi <shy828301@gmail.com>, Vlastimil Babka <vbabka@suse.cz>, Alex Sierra <alex.sierra@amd.com>, Vincent Whitchurch <vincent.whitchurch@axis.com>, Anshuman Khandual <anshuman.khandual@arm.com>, Li kunyu <kunyu@nfschina.com>, Liu Shixin <liushixin2@huawei.com>, Hugh Dickins <hughd@google.com>, Minchan Kim <minchan@kernel.org>, Joey Gouly <joey.gouly@arm.com>, Chih-En Lin <shiyn.lin@gmail.com>, Michal Hocko <mhocko@suse.com>, Suren Baghdasaryan <surenb@google.com>, "Zach O'Keefe" <zokeefe@google.com>, Gautam Menghani <gautammenghani201@gmail.com>, Catalin Marinas <catalin.marinas@arm.com>, Mark Brown <broonie@kernel.org>, "Eric W. Biederman" <ebiederm@xmission.com>, Andrei Vagin <avagin@gmail.com>, Shakeel Butt <shakeelb@google.com>, Daniel Bristot de Oliveira <bristot@kernel.org>, "Jason A. Donenfeld" <Jason@zx2c4.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Alexey Gladkov <legion@kernel.org>, x86@kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Dinglan Peng <peng301@purdue.edu>, Pedro Fonseca <pfonseca@purdue.edu>, Jim Huang <jserv@ccns.ncku.edu.tw>, Huichun Feng <foxhoundsk.tw@gmail.com> Subject: [PATCH v5 10/17] mm/gup: Trigger break COW PTE before calling follow_pfn_pte() Date: Fri, 14 Apr 2023 22:23:34 +0800 Message-Id: <20230414142341.354556-11-shiyn.lin@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230414142341.354556-1-shiyn.lin@gmail.com> References: <20230414142341.354556-1-shiyn.lin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Stat-Signature: u9rjtwz39z8fheydehgg98ueepc3wm75 X-Rspam-User: X-Rspamd-Queue-Id: A395D40011 X-Rspamd-Server: rspam06 X-HE-Tag: 1681482354-220672 X-HE-Meta: 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 gwp47SeO 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: <linux-mm.kvack.org> |
Series |
Introduce Copy-On-Write to Page Table
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expand
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diff --git a/mm/gup.c b/mm/gup.c index eab18ba045db..325424c02ca6 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -544,7 +544,8 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) == (FOLL_PIN | FOLL_GET))) return ERR_PTR(-EINVAL); - if (unlikely(pmd_bad(*pmd))) + /* COW-ed PTE has write protection which can trigger pmd_bad(). */ + if (unlikely(pmd_write(*pmd) && pmd_bad(*pmd))) return no_page_table(vma, flags); ptep = pte_offset_map_lock(mm, pmd, address, &ptl); @@ -587,6 +588,11 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, if (is_zero_pfn(pte_pfn(pte))) { page = pte_page(pte); } else { + if (test_bit(MMF_COW_PTE, &mm->flags) && + !pmd_write(*pmd)) { + page = ERR_PTR(-EMLINK); + goto out; + } ret = follow_pfn_pte(vma, address, ptep, flags); page = ERR_PTR(ret); goto out;
In most of cases, GUP will not modify the page table, excluding follow_pfn_pte(). To deal with COW PTE, Trigger the break COW PTE fault before calling follow_pfn_pte(). Signed-off-by: Chih-En Lin <shiyn.lin@gmail.com> --- mm/gup.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)